Valve for controlling gas flow

ABSTRACT

A gas valve is adapted for controlling the flow of a medical gas for oxygen therapy in case of spontaneous breathing. The gas valve comprises a connection component for connecting the gas valve to an external supply; and a regulating system configured for selecting and supplying a pulsating flow of medical gas or a continuous flow of medical gas, in which the regulating system comprises a first sub-regulating system for supplying a pulsating flow and a second sub-regulating system for supplying a continuous flow.

FIELD OF THE INVENTION

In general, this invention concerns systems for the supply of oxygen,for example to patients in hospitals. More specifically, the presentinvention relates to a gas valve for the supply of oxygen, a systemcontaining such a gas valve, and the use of such a gas valve forcontrolling the gas flow, e.g. oxygen gas flow intended for patients inhospitals.

BACKGROUND OF THE INVENTION

The use of gases in medical applications is widespread. One of the gasesoften administered to patients for medical reasons is oxygen. In view ofthe fact that administering oxygen is often essential for preventingdamage to tissue, avoiding life-threatening situations or saving apatient from a life-threatening situation, hospitals distribute oxygenusing a pipeline network up to the bed of nearly each patient. Theconventional form of administering oxygen through a pipeline network isin a continuous manner. A flow meter can be set to the flow rate thatthe patient needs (1 l/min up to 15 l/min continuously or higher). Thisway the oxygen flows continuously from the source to the patient via anasal cannula during inhaling and exhaling. The flow meter is pluggedinto the low-pressure oxygen socket (usually between 3.6 and 5.5 bars)on the wall behind the patient's bed. A moisturizer can be attached tothe bottom side to prevent drying up of the nasal mucous membrane.

The lungs can only utilise the first phase of inhalation to exchangeoxygen with the blood circulation. It is clear that oxygen can no longerbe ‘consumed’ during the expiration phase (exhalation). However, duringthe last phase of inhalation too, only the large bronchial tube thatdoes not participate in the diffusion process of oxygen is filled. Gasvalves for the pulsating supply of medical gases are based on thisprinciple: oxygen is purposefully administered during the first phase ofinhalation by the patient. This way a maximum oxygen intake is achievedand the oxygen that is not used is minimised. This results in savingswithout impacting the oxygen therapy.

Various gas valves have been developed during the past 20 years whichare based on the principle of discontinuous oxygen administration inorder to increase the mobility of patients that use oxygen cylinders athome and/or to increase the autonomy of recipients. After all, the useof gas valves for mobile patients saves oxygen, which results in a lowerconsumption and consequently creating longer autonomy, i.e. 3 to 5 timeslonger than the autonomy achieved with continuous administration.

Most gas valves are based on a regulating system in which nasalinhalation activates the gas valve. The underpressure activates andopens an oxygen valve through which an oxygen pulse (aka bolus) isgenerated. Detecting the inhalation and supplying the oxygen occurs bymeans of a nasal cannula. A nasal cannula can be a one-channel system(detection and supply occur through the same channel) or a two-channelsystem in which one channel is used for detecting the inhalation and theother channel is used for supplying the oxygen.

EP1325762 describes a one-channel system for the supply of medicalgases. The system provides an oxygen bolus in case of detectinginhalation and provides a period of delay following the oxygen bolus inorder to avoid a redundant double oxygen pulse.

US 2008/0173304 A1 describes a pneumatic valve for medical gases thatcombines the typical advantages of operating a one-channel nasal cannulaand a two-channel nasal cannula. The pneumatic medical gas valvegenerates a gas pulse based on the detection of nasal inhalation andprevents generating a double pulse by applying a pneumatically induceddelay.

US 2007/0017520 A1 describes a device for administering oxygen in whichgas is released in case of inhalation and in which the gas flow isinterrupted by a dedicated pneumatic system.

FR2813799 A1 describes a gas valve for oxygen in which a continuous flowand a pulsating administration are possible. The gas valve consists oftwo channels to the patient: one channel takes care of supplying theoxygen and the other channel ensures the detection of inhalation.Furthermore, the gas valve has a pressure regulator so that the gasvalve can be connected to a gas cylinder under high pressure.

U.S. Pat. No. 4,932,402 describes a gas valve that provides auser-specific oxygen supply based on the measured breathing of thepatient using an electronic control. Moreover, the system is customisedto switch to a continuous oxygen flow in case of power failure or pooroperation.

U.S. Pat. No. 5,038,770 describes another valve that has a safeguard incase the control system for pulsating supply fails or if there is apower failure.

Most of the aforementioned systems are suitable for home use in which agas cylinder is used.

Hospitals have to cope with a large circulation of patients. That meansthat systems with a complex adjustment to the patient's individual needsare time-consuming for the patient and for the medical staff. Inaddition, hospitals have a large variety of medical gas therapies thatare used even during the treatment of one and the same patient. Thisdiffers significantly from home devices used by an individual patient inwhich the patient usually sets the correct adjustment only once (or alimited number of times) and after that, he/she can usually use the sameadjustment. In addition, the current technology does not enablegenerating a pulse dosage of more than 6 l/min. The result is that theavailable economizer valves are not suitable for all patients andconsequently, cannot be used efficiently in hospitals.

Therefore, a valve for checking the flow of medical gas that can be usedeffectively in specific institutional environments such as hospitals isrequired. In addition, there is a need for a medical gas flowcontrolling valve that enables a larger flow of medical gas (e.g., morethan 6 l/min).

SUMMARY OF THE INVENTION

It is an object of embodiments according to the present invention toprovide a valve for controlling the gas flow of medical gases that canbe used effectively in hospitals as well as a method for its use.

It is an advantage of at least some embodiments of the present inventionthat it allows an efficient switch between various settings of the gasvalve, enabling the use of the valve in frequently changing situationsapplicable to hospitals, for example.

It is an advantage of at least some embodiments of the present inventionthat it allows the production of a gas valve that enables setting alarge gas flow (e.g., a gas flow with a flow rate of more than 6 l/min).

It is an advantage of embodiments of the present invention that itallows simple adjustment of the therapy, for example, as a result of adifferent process of rehabilitation or as a result of the patient's needfor another type of therapy.

It is an advantage of embodiments of the present invention that itprovides functioning of the gas valve as an economizer valve: this canresult in a considerable reduction of the quantity of gas used.

It is an advantage of at least some embodiments of the present inventionthat it provides optimising the use of medical gases: this can result inreduced consumption of medical gases (average is more than 50% e.g.,more than 70% or 80%) compared with the use of a continuous gas flow.

It is an advantage of at least some embodiments of the present inventionthat it poses fewer burdens on the environment due to the potentialreduction in the production of medical gases and the reduction intransport time of medical gases as a result of the reduced consumptionof oxygen.

It is an advantage of at least some embodiments of the present inventionthat it provides a more fire-proof environment because fewer unusedmedical gases such as oxygen are distributed in the rooms.

It is an advantage of embodiments of the present invention that itallows enabling an easy switch from continuous flow to pulsating supplyand vice versa.

It is an advantage of at least some embodiments of the present inventionthat it allows enabling continuous supply with high flow rates inaddition to a pulsating supply. An additional advantage is that such acontinuous supply can occur with high accuracy.

It is an advantage of at least some embodiments of the present inventionthat it provides initial operation of the gas valve (i.e., every time itis switched on after closing the gas valve or after connecting to thegas supply network) in the mode of pulsating supply so that a saving isachieved, even if the medical staff or the user does not adjust thevalve.

It is an advantage of at least some embodiments of the present inventionthat the pulsating mode of the gas valve can operate independently ofthe settings for the continuous mode of the gas valve.

It is an advantage of at least some embodiments of the present inventionthat a safeguarding element is built into the gas valve so that onlyconnecting to a specific gas connection for a specific medical gas ispossible.

It is an advantage of at least some embodiments of the present inventionthat a simple switch to continuous flow is possible, for example, if thepulsating supply makes too much noise when falling asleep or if thepatient breathes too heavily through his/her mouth (resulting ininsufficient underpressure of the economizer system to activate theoxygen pulse) or at critical moments in which the doctor wishes toswitch to continuous flow or to higher flow rates.

The aforementioned objective is achieved by a device and a methodaccording to the embodiments of the current invention.

The present invention relates to a gas valve adapted for controlling theflow of a medical gas for oxygen therapy in case of spontaneousbreathing, the gas valve comprising a connection component forconnecting the gas valve to an external supply, and a regulating systemconfigured for selecting and supplying a pulsating flow of medical gasor a continuous flow of medical gas, in which the regulating systemcomprises a first sub-regulating system for supplying a pulsating flowand a second sub-regulating system for supplying a continuous flow.

The first sub-regulating system and the second sub-regulating system maybe controlled by two distinct actions in the regulating system.

The second sub-regulating system may be a flow rate regulator equippedfor at least controllably selecting the flow rate of the continuous flowin the range of 2 litres per minute to 8 litres per minute.

The second sub-regulating system may be a flow rate meter.

The gas valve furthermore may be configured so that the secondsub-regulating system indicates the amount of medical gas used during apulsating flow regime.

The flow rate of the pulsed flow and/or the flow rate of the continuousflow may be selectable in a stepwise manner.

A state of the first sub-regulating system may not influence a settingof the second sub-regulating system when the second sub-regulatingsystem is used for controlling a continuous flow.

A state of the second sub-regulating system may not influence a settingof the first sub-regulating system when the first sub-regulating systemis used for controlling a pulsed flow.

The first sub-regulating system and the second sub-regulating system maybe implemented by the same control element.

The control element may be a rotating element and wherein selection inthe first sub-regulating system Is performed by rotating the controlelement in a first direction while selection in the secondsub-regulating system is performed by rotating the control elements inthe other direction.

The first direction may be one of a clockwise or counterclockwisedirection of the rotating element and wherein the second direction Isthe other of the clockwise or counterclockwise direction of the rotatingelement

The gas valve may be adapted for allowing oxygen therapy in case ofspontaneous breathing, wherein the pulsating flow of medical gas isbeing based on underpressure generated by inhalation of the patient.

The second sub-regulating system may be adapted for enabling a flow rateof more than 10 litres of medical gas per minute.

The gas valve may be configured so that the first sub-regulating systemand the second sub-regulating system are applied in parallel gaschannels.

The gas valve system may be configured for automatically initiating thevalve in pulsating mode.

The gas valve may be based on solely mechanical and pneumatic operation.

The gas valve may be adapted for closing the pulsating flow on the basisof a pre-determined signal.

The gas valve may comprise a system cut-off valve for cutting off thegas flow, which is activated by disconnecting the one-channel nasalcannula or the two-channel nasal cannula from the one-channelfeedthrough or two-channel feedthrough.

The gas valve may be provided with a one-channel feedthrough in order toconnect a one-channel nasal cannula for supplying medical gas to apatient or where the gas valve is provided with a two-channelfeedthrough in order to connect a two-channel nasal cannula forsupplying medical gas.

The connection component is adjusted for connecting the gas valve to anexternal supply network of medical gases at a pressure lower than 50bars.

In another aspect, the present invention also relates to a gas valve forcontrolling the flow of medical gas for oxygen therapy in case ofspontaneous breathing in which the gas valve comprises a connectioncomponent for connecting the gas valve to an external supply and aregulating system that is configured for selecting and supplying apulsating flow of medical gas or a continuous flow of medical gas, andwherein the regulating system has a flow-rate regulator for controllablysetting the flow rate of the continuous flow of medical gas.

It is an advantage of at least some embodiments according to the presentinvention that an economizer system for administering medical gases(e.g., oxygen) is provided that is suitable for use in specialisedinstitutions such as hospitals, old age homes and nursing homes, so thatthese specialised institutions can optimise the administration ofmedical gases in the first phase of inhalation. As a result, the use ofthese economizer systems (aka valves with supply-on-demand) achievesconsiderable saving of medical gases in specialised institutions.

It is an advantage of at least some embodiments according to the presentinvention that an economizer system is provided that is specificallyadapted to the needs of stationary use (e.g., hospital beds).

It is an advantage of at least some embodiments of the present inventionthat additional moisturizing systems can be avoided by providing asetting for pulsating flow, reducing the risk of infections. Theexternal supply of some embodiments can be a supply network for medicalgases with a pressure lower than 50 bars or it can be a gas cylinder.

The flow rate regulator can be equipped minimally for the controllablesetting of the flow rate of the continuous flow with a range of 2 l/minup to 8 l/min.

It is an advantage of at least some embodiments according to the presentinvention that there is a controllable flow even for flow rates that arehigher than 6 l/min. The flow rate regulator can be equipped minimallyfor the controllable setting of the flow rate of the continuous flowwith a range of 2 l/min up to more than 10 l/min, while some embodimentshave a range of more than 15 l/min or even more than 25 l/min. Otherexamples of ranges in which valves (e.g., valves for paediatricapplications) can be controllably set are 0-200 cc/min, 0-1 l/min, 0-3l/min and 1-2 l/min, for example.

It is an advantage of at least some embodiments of the present inventionthat a high flow rate can be provided in a controllable manner so thatthe gas valve can also be used for more critically ill patients.

In view of the fact that specialised institutions have to cope with aquick turnover of patients, it is an advantage to use gas valves bothfor less critically ill patients and more critically ill patients.

The flow rate regulator can be a flow rate meter such as a flow meter.The gas valve can be configured so that the flow rate regulator does notimpact the flow of medical gas if the regulating system is set topulsating flow.

It is an advantage of at least some embodiments of the present inventionthat the gas valve can operate in pulsating mode, independent of thestatus of the flow rate regulator, so that the medical staff or user isnot required to execute specific actions.

The regulating system can consists of a first sub-regulating system forsupplying a pulsating flow and a second sub-regulating system forsupplying a continuous flow in which the flow rate regulator is part ofthe second sub-regulating system and in which the gas valve isconfigured in such a way that the first sub-regulating system and thesecond sub-regulating system are in parallel gas channels.

It is an advantage of at least some embodiments according to the presentinvention that, if the gas valve is used in the pulsating position, thestatus of the second sub-regulating system does not affect the deliveredgas supply.

The gas valve can be configured so that the regulating system is in amode of pulsating gas flow at the start of the flow.

It is an advantage of at least some embodiments according to the presentinvention that the gas valve can start standard in pulsating flow,providing a saving regimen in case the valve is not adjusted.

For activating the second sub-regulating system, an accessory selectionsystem might need to be activated. It should be de-activated when thecontinuous flow is interrupted.

It is an advantage of at least some embodiments according to the presentinvention that additional actions should be undertaken to generate thecontinuous flow in order to avoid the spontaneous and superfluous use ofthe continuous flow setting.

The gas valve can operate mechanically and pneumatically. An additionaladvantage is that powering for the valve's operation (e.g., by abattery) can be avoided, which reduces costs and maintenance.

The regulating system can enable the selection of the flow type via aclick system.

It is an advantage of embodiments of the present invention that the gasvalve can be switched from pulsating flow to continuous flow in a simplemanner (via one click or a few clicks, for example).

Furthermore, the regulating system can be configured to select andsupply various types of pulsating flows.

It is an advantage of embodiments of the present invention that the gasvalve enables the selection of a pulsating flow that corresponds with acertain flow rate.

The gas valve can be adjusted, e.g. by adjusting the operation of theregulating system for supplying the pulsating flow, to close thepulsating flow based on a pre-determined signal, for example, ifunderpressure is lacking, which indicates that nasal inhalation ismissing.

The gas valve can include a closing mechanism to close the pulsatingflow and the continuous flow on the basis of a pre-determined signal.

It is an advantage of at least some embodiments of the present inventionthat the gas valve can be a valve with supply-on-demand, which canprovide a stop function for the pulsating flow and the continuous flow.This can be useful in specialised institutions, for example, when thepatient is examined. The pre-determined signal can be the lack ofunderpressure over a certain period (e.g., if the patient removes thenasal cannula through which the flow occurs) and/or a one-way valvesignal ‘present’ or ‘missing’ in the system.

The gas valve can be equipped with a one-channel lead-through forconnecting a one-channel nasal cannula for supplying the medical gas tothe patient.

It is an advantage of embodiments of the present invention that the gasvalve can operate together with a one-channel nasal cannula, which areless expensive.

The gas valve can be equipped with a two-channel lead-through forconnecting a two-channel nasal cannula for supplying the medical gas.

It is an advantage of embodiments of the present invention that the gasvalve can operate together with more sophisticated two-channel nasalcannulas, which provide more flexibility and control.

The valve can also include a system cut-off valve for closing the flow,which is activated by disconnecting the one-channel nasal cannula fromthe one-channel lead-through or the two-channel nasal cannula from thetwo-channel lead-through.

The flow rate regulator can enable a flow rate of medical gas of morethan 15 l/min or more than 25l/min.

The flow rate regulator can be adjusted to set and control the flow rateof the continuous supply to one of a few pre-determined flow rates.

The flow rate regulator can be adjusted to set and control continuouslythe flow rate of the continuous supply.

The regulating system can be adjusted to supply a pulsating flow ofmedical gas with a flow rate of more than 6l/min during pulsation.

The current invention also relates to a kit of parts, including theaforementioned gas valve and a nasal cannula for the administration ofmedical gas in which the nasal cannula can be connected to the gasvalve.

In addition, the current invention also relates to the use of theaforementioned gas valve for checking the flow of a medical gas.

Specific and preferred aspects of the invention are included in theattached independent and dependent conclusions. Characteristics of thedependent conclusions can be combined with the characteristics of theindependent conclusions and with characteristics of other dependentconclusions as indicated and not solely as explicitly stated in theclaims.

SHORT DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a schematic representation of a gas valve accordingto an embodiment of the present invention.

FIG. 2 illustrates a schematic representation of a gas valve accordingto an embodiment of the present invention in which a regulating systemfor pulsating flow is in series with a regulating system for continuousflow.

FIG. 3 illustrates a schematic representation of a gas valve accordingto an embodiment of the present invention, which includes a parallel gaslead-through and which has the regulating system for pulsating flow inone lead-through and the regulating system for continuous flow inanother lead-through.

FIG. 4 shows the oxygen saturation achieved for a first set ofexperiments in using a gas valve according to an embodiment of thepresent invention.

FIG. 5 shows the saving factor for a first set of experiments in using agas valve according to an embodiment of the present invention.

FIG. 6 shows a gas valve according to an embodiment of the presentinvention in which the flow type and the flow rate can be selected witha single selection element.

FIG. 7 illustrates the oxygen consumption in a surgery ward whenchanging utilisation of a gas valve according to an embodiment of thepresent invention and a gas valve with continuous flow according to thecurrent state of technology.

FIG. 8 illustrates the average oxygen consumption when changingutilisation of a gas valve according to an embodiment of the presentinvention and a gas valve with continuous flow according to the currentstate of technology.

FIG. 9A and FIG. 9B illustrate two cross-sectional views of an internalportion of the gas valve according to an embodiment of the presentinvention.

FIGS. 10 to 12 illustrate alternative embodiments of a gas supply systemaccording to the present invention.

The figures are only schematic and are not limiting. For illustrativepurposes, the figures might exaggerate the dimensions of some componentsand these dimensions are not shown on scale. The dimensions and relativedimensions do not necessarily correspond with the ones of the practicalembodiments of the invention.

Reference numbers in the conclusions may not be interpreted to limit thescope of protection of rights.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

The current invention is described while referring to specificembodiments and to certain figures, but the invention is not limited bythese referrals. The invention is only limited by the claims.

It should be noted that the terms “comprise” and “contain” as used inthe claims should not be interpreted as ‘limiting to the means describedbelow’. These terms do not exclude other elements. These should beinterpreted as specifying the presence of the stated and referredfeatures, values, steps or components, but do not exclude the presenceor addition of one or more other features, values, steps, components orcombinations/groups of these. Therefore, the scope of the expression ‘anarrangement comprising means A and B’ should not be limited toarrangements only consisting of components A and B. Regarding thecurrent invention, it means that A and B are the only relevantcomponents of the arrangement.

Referral throughout this specification to ‘one embodiment’ or ‘anembodiment’ means that a specific feature, structure or characteristicdescribed in relation to the embodiment is included in at least oneembodiment of the current invention. Therefore, all appearances ofexpressions ‘in one embodiment’ or ‘in an embodiment’ at several placesthroughout this specification do not necessarily refer to the sameembodiment, but they can refer to the same embodiment. Furthermore, thespecific features, structures or characteristics can be combined in anysuitable manner (as may be clear to a professional on the basis of thisnotification) in one or more embodiments.

Similarly, it should be understood that sometimes the description ofsample embodiments of the invention groups various features of theinvention in a single embodiment, figure or its description for thepurpose of streamlining the disclosure or assisting in understanding oneor more different inventive aspects. This method of disclosure shouldnot be interpreted in any way as a representation of an intention thatthe invention requires more features than are mentioned explicitly ineach conclusion. Rather (as the following conclusions represent)inventive aspects are in fewer than all the features of a singledisclosed embodiment. Therefore, the claims that follow the detaileddescription are explicitly included in this detailed description, witheach individual claim as a separate embodiment of this invention.

In addition—while some embodiments described in this detaileddescription contain some features, but do not contain other featuresincluded in other embodiments—combinations of features of differentembodiments are intended as within the scope of the invention andconstitute these different embodiments as should be understood by theperson skilled in the art. For example, the following claims can use anyof the described embodiments in any combination.

It should be noted that the use of specific terminology in describingcertain features or aspects of the invention should not be interpretedto imply that the terminology is redefined to be limited to specificcharacteristics of the features or aspects of the invention with whichthis terminology is linked.

In the embodiments of the present invention, wherever reference is madeto ‘flow’ or ‘gas flow’, the reference is to the flows of gas in whichcase the reference can be to a pulsating flow of gas as well as to acontinuous flow of gas.

In the embodiments of the current invention, wherever reference is madeto ‘flow rate’, the reference is to the variable that expresses thevolume of gas that flows through the system per time unit.

In the embodiments of the present invention, wherever reference is madeto ‘oxygen therapy’, reference is to a therapy in which oxygen is addedto achieve a concentration of oxygen that is higher than the standardconcentration in the ambient air.

In embodiments of the current invention, pulsating gas supply isactivated preferably by breathing i.e., inhalation can typically triggera gas pulse while during exhalation no gas pulse is provided.

Embodiments of the current invention are suitable preferably for personsor animals with spontaneous breathing.

Where in embodiments of the present invention reference is made to aflow rate meter, the latter may be a flow rate indicating means thatindicates the flow rate in a qualitative manner, as well as a flow rateindicating means that indicates the flow rate in a quantitative manner.

Where in embodiments of the present invention reference is made to afirst sub-regulating system for supplying a pulsating flow and a secondsub-regulating system for supplying a continuous flow this encompassessub-regulating systems for controlling the pulsating flow and forcontinuous flow. These may be implemented as distinct control elementsbut alternatively also may be implemented as a single control elementwherein distinct actions on the control element provide for control ofthe pulsating flow and the continuous flow.

In one aspect, the present invention relates to a gas valve adapted forcontrolling the flow of a medical gas for oxygen therapy in case ofspontaneous breathing. The gas valve comprises a connection componentfor connecting the gas valve to an external supply and a regulatingsystem configured for selecting and supplying a pulsating flow ofmedical gas or a continuous flow of medical gas, in which the regulatingsystem comprises a first sub-regulating system for supplying a pulsatingflow and a second sub-regulating system for supplying a continuous flow.Different embodiments are illustrated in drawings FIG. 1 to FIG. 12

In some embodiments, the present invention concerns a gas valve forchecking the flow of medical gas. A typical example of administeringmedical gas to patients is oxygen therapy, although embodiments of theinvention are not limited to this. As examples, FIG. 1 , FIG. 2 and FIG.3 show schematic representations of sample gas valves, althoughembodiments of the present invention are not limited to this. Gas valve100 according to embodiments of the current invention includes aconnection component 110 to connect gas valve 100 to an external supply.Such an external supply can be an external supply network 1 for medicalgases at a pressure lower than 50 bars (e.g., 10 bars or lower). It isan advantage that gas valves are provided for specific applications insupply networks such as in hospitals. Alternatively, connectioncomponent 110 can be adjusted to connect to a gas canister or gascylinder at a pressure higher than 50 bars (e.g., approx. 200 bars).Such cylinders enable an uninterrupted supply of oxygen during oxygentherapy in case the patient is moved from one department to another. Thedisadvantage is that consumption must be monitored so that the cylindersare replaced on time. In a hospital environment, the same problems occurwhen using cylinders as when using a supply network: need for a simpleswitch in therapy due to a change in patients or even a switch intherapy of the same patient, autonomy, consumption, need for supplyinghigh flow rates, etc. In embodiments according to the current invention,connection component 110 can be adjusted to correspond with typicalconnections in the supply network. This can be a connection of a shapelaid down in the law, for example, according to DIN norms, CARBA norms,BOC norms or AFNOR norms. It should be clear that the precise type of aninstalled connection is not limited to embodiments of the currentinvention. For example, such an external supply network 1 can be anetwork for distributing medical gases in a hospital and can supply sucha medical gas at a pressure in the range of 3.3 bars up to 5.5 bars orsimilar. A commonly found gas supply network 1, which one finds inhospitals, is the facility of oxygen connections for patients in eachroom. In a specific embodiment of the current invention, the connectioncomponent is equipped with a special geometry that fits a connection toa specific gas supply network eliminating any errors between differentgas supply networks. Gas valve 100 according to embodiments of thecurrent invention also includes the regulating system 120. This systemis configured to select and supply a pulsating or continuous flow ofmedical gas. Regulating system 120 also includes flow rate regulator 142for setting the flow rate of the continuous flow. Flow rate regulator142 enables regulating or setting the flow rate of the continuous flow.In some embodiments, flow rate regulator 142 is a flow rate meter i.e.,a device that measures the flow rate quantitatively. Flow rate regulator142 can be equipped to select a flow rate out of a set of pre-determinedflow rates and/or can be equipped to enable a continuous selection ofthe flow rate. Selecting a pulsating flow of medical gas can mean asubstantial saving in the quantity of medical gas used (e.g., oxygen)without impacting the quality of the therapy. Furthermore, using apulsating flow has the essential advantage that it is more comfortablefor the patient. Continuous medical gas administration (for example,oxygen administration) causes dryness of the nasal membrane, pharynx andoral cavity. Some hospitals use a moisturizer to solve this problem but,in the last years, this is no longer recommended due to the higherinfection risk. Using pulsating administration, the drying up of thenasal membrane is minimal, which increases the patient's comfort. Inother words, the moisture balance in the nose, pharynx and oral cavityis retained better by using the pulsating technology instead of thecontinuous technology, resulting in more comfort for the patient.

On the other hand, medical personnel want to use continuous gas flowwith high flow rates at various critical moments such as in case ofresuscitation or after a fall. In addition, continuous supply of medicalgas can also be necessary if the pulsating supply is based on nasalinhalation (e.g., creation of underpressure, measured via a nasalcannula) and if the patient cannot cope with this type of inhalation.Approx. 20% of the patients show mixed breathing (sometimes through themouth, sometimes through the nose). Furthermore, some people are tooconfused so that they do not understand that nasal inhalation isnecessary for oxygen therapy, for example. Another situation in whichpulsating flow of medical gas is not always advised is when using gasvalves that are relatively noisy. The pulsating dosage in existing gasvalves delivers a bolus of medical gas when the patient inhales. Thisproduces a light puffing noise. Usually, this light puff is not aproblem during the daytime, but some patients are sensitive to thisnoise when trying to fall asleep. Furthermore, a flow rate higher than 6l/min is often needed, which in some embodiments of the currentinvention can only be administered in continuous mode. Therefore,continuous gas flow might be necessary for these people or in thesesituations. Gas valve 100 according to embodiments of the currentinvention includes therefore flow rate regulator 142 in order to enableselecting the flow rate in case of continuous administration. If supplyof medical gas is critical, an accurate administration and as a result,creating an accurate flow is advantageous. Therefore, flow rateregulator 142 can be a flow rate meter in some embodiments. Regulatingsystem 120 in gas valve 100 according to embodiments of the currentinvention enables you to easily and efficiently select a pulsating or acontinuous gas flow.

The advantage of gas valves 100 according to embodiments of the currentinvention is that they enable a simple selection setting. This makes itbetter for medical personnel who often are in a busy and stress-inducingenvironment in which they have to perform many tasks.

An additional advantage of embodiments according to the currentinvention is that gas valves 100 can easily switch from continuous topulsating settings and vice versa. This design can be used in hospitalsfor all kinds of patients and in all types of circumstances. Asindicated above, various circumstances sometimes require changes: notonly changes between patients, but also a different type of therapyneeded for the same patient. For example, the condition of a patient cansometimes improve during his/her stay in the hospital and it cansometimes deteriorate, resulting in the need to adjust the oxygentherapy (usually less oxygen is administered as the patient's conditionimproves).

In addition, gas valve 100 according to embodiments of the currentinvention has a lead-through 150 (also referred to as an outlet) forconnecting a system to lead the generated gas flow to the patient. Aclassic example of such a system is a nasal cannula. Lead-through 150can be a one-channel or a two-channel lead-through (e.g., for connectinga one-channel or two-channel nasal cannula). A two-channel lead-throughhas two channels in which one channel is used for supplying the medicalgas and the other channel is used for detecting the nasal inhalation ata specific moment. The lead-through can have a fitting connection fornasal cannulas available on the market for supplying medical gases topatients. Lead-through 150 can have a specific geometry in a specificembodiment in order to correspond to a specific geometry of the system'sconnection that supplies the generated gas flow to the patient (e.g., anasal cannula with a connection of a specific geometry). This willprevent a situation in which the system supplying the generated gas flowto the patient is connected by mistake to the wrong pipeline (e.g., acompressed air pipeline).

In some embodiments, the system can be adjusted to operate with atwo-channel nasal cannula and the system used for detecting the nasalinhalation at a specific time can be used to initiate the gas pulse. Inother words, the pulse operation can be regulated on the basis of thedetected signal.

In other embodiments, the valve is adjusted to operate with aone-channel nasal cannula and the pulse operation is initiated bycreating underpressure.

In one embodiment of the valve, a pulsating oxygen supply can occur asfollows: A filling space is filled by means of a constant inputpressure. A closing port seals off the filling space so that the spacestays closed without underpressure. The underpressure, which isgenerated by the inhalation of the patient (inhalation through thenose), sets the closing port in motion and opens the cavity, resultingin the administration of the gas in the cavity to the patient in asingle bolus. In this case, the valve is preferably made in such a waythat it closes hermitically if there is no underpressure, and it opensat minimum underpressure created by the nasal inhalation. Ingeneral—inherent to the operation—a closing port can be installed tointerrupt the pulsating flow if the patient does not generateunderpressure by nasal inhalation.

It should be noted that embodiments of the present invention are notlimited by the basic principle according to which the pulses aregenerated in the valve. Generating pulses can occur on the basis of amechanism according to the current state of technology. In someexamples, the pulses can also be generated in valves with a more complexgeometry. One example—but not limited to this example—is the pulsegeneration via multi-stage valves that enable a delicate detection ofthe inhalation in the first stage and that supply a sufficiently largeoxygen pulse by activating the next stages. In addition to more complexgeometries, other features such as safety mechanisms can also be builtin. One example of such a feature is limiting the number of pulses thatare generated, in case the patient starts to hyperventilate. Systemfeatures for generating pulses are well-known to professionals andtherefore, will not be explained in detail here.

According to embodiments of the current invention, regulating system 120can consist of a first sub-regulating system 130 for supplying apulsating flow and a second sub-regulating system 140 containing theflow rate regulator 142 for supplying a continuous flow, and a selectionis made between the first sub-regulating system 130 and the secondsub-regulating system 140. In one embodiment, both sub-regulatingsystems are in series as illustrated in FIG. 2 . This implies that thesecond sub-regulating system should be open in order to guarantee theproper operation of the sub-regulating system for supplying a pulsatingflow. The sequence of the first and the second sub-regulating system canalternate.

In a preferred embodiment, the first sub-regulating system 130 and thesecond sub-regulating system 140 are in parallel. Such an economicalsystem is shown in FIG. 3 . The advantage of this is that the status ofthe flow rate regulator does not impact the operation of the firstsub-regulating system when the valve is set to supply a pulsating flow.

Furthermore, the design of the valve according to embodiments of thecurrent invention can be such that the system in standard settingsupplies a pulsating flow spontaneously (e.g., any time a gas flow isstarted), unless the user selects a continuous flow. In other words, thevalve in a preferred embodiment is made in such a way that the standardsetting supplies the pulsating flow of medical gas, while the other modecan be obtained via selection. An element can also be providedthat—based on a signal—sets the valve in the standard setting in whichit supplies a pulsating flow. This element can initiate a standardsetting every time the continuous flow is de-activated or if the valveis de-activated. Such an additional element can be controlledpneumatically, mechanically or electronically, and can be based on adetection signal (e.g., using a one-way valve that is installed in thegas valve). In some embodiments, this element can actively prevent thecontinuous flow, unless an action is performed so that the selection ofa continuous flow becomes an active choice. It contributes to theruggedness and the maintenance-friendliness of the system, if theelement is only controlled pneumatically or mechanically, because thereis no need to change batteries.

In a preferred embodiment, the valve is based on pneumatic or mechanicaloperation without electronics to boost the ruggedness.

In some embodiments, an emergency button can be fitted. By pushing thisbutton you select the continuous mode in order to switch quickly to acontinuous mode at critical moments such as in case of resuscitation orafter a fall.

In a embodiment of the valve in which activating the emergency buttontriggers a continuous mode, the mechanism for pulsating and/orcontinuous mode are usually in parallel.

According to embodiments of the current invention, the valve can containelectronic components, although preferably these are made pneumaticallyand/or mechanically. The pneumatic valves are often more suitable forlong-term use in hospitals, for example, because they can be set in asimple manner and because they do not require batteries. Therefore, theycan be used for years without requiring additional actions ormaintenance. In addition, a significant advantage of not needing powersupply is the saving in costs and maintenance time.

In a embodiment of the current invention, the valve can also haveone-stage control—possibly including a memory button as describedbelow—so that the entire control can be by operating one selectionelement. Such a system avoids that the user first needs to set a certainflow in the first selection element and subsequently, needs to set theselected administration mode in another selection element. An example ofsuch a selection element is one that can move in an initial direction inwhich the flow rate is selected and that can move in a second directionfor selecting between pulsating or continuous mode. In one example, theselection element is a selection ring in which the flow rate can beselected by rotating the ring and in which a selection between pulsatingand continuous mode is made by shifting the ring in a direction otherthan the rotating direction. FIG. 6 shows such a selection ring in which(at the left-hand side) a valve is shown that is set to pulsation modeby putting the selection ring in the top position and (at the right-handside) a valve is shown that is set to continuous mode by shifting theselection ring downwards. This embodiment according to the currentinvention has the advantage that errors cannot occur (for example, byoperating just one of the two selection elements) because the entireselection is made using one and the same selection element.

In another embodiment, the valve can optionally have a closing mechanism160. This mechanism can close the pulsating and the continuous flow ofmedical gas (e.g., if the patient is absent or does not use oxygen) andthat prevents superfluous flow of medical gas. This closing mechanismcan be controlled pneumatically, mechanically, electronically or in anyother manner. Closing mechanism 160 can be installed before and afterthe pulsating and/or continuous mechanism. In another example, this canalso be a mechanical On/Off button. Closing system 160 can closeautomatically if the patient does not utilise medical gas supply and itcan be controlled by the detection or the non-detection of any nasal ororal inhalation, etc. This additional closing mechanism can prevent thewaste of medical gas. Therefore, the system can have an additionalfunctionality with which the valve will close, but in which the mostrecently set flow rate is stored in memory. This memory functionincreases the user-friendliness, also for the oxygen supplier, becausehe/she does not have to remember the required flow rate in case of notusing oxygen temporarily. It also reduces the risk that the oxygensupplier leaves the valve open and causes additional waste.

In certain situations (e.g., emergency situations or for critically illpatients), a specific embodiment can also have a mode, which supplies acontinuous flow (independent of the detection of breathing), for asystem in which the continuous flow is usually controlled by thepresence or absence of breathing in order to prevent waste if thepatient is absent. Such a embodiment can have three modes: a pulsatingmode triggered by the patient's breathing, a continuous mode in whichthe breathing is used to check whether the patient uses the system, anda continuous mode independent of the patient's breathing. The lattermode guarantees the supply under all circumstances for critically illpatients.

In a specific embodiment, the valve also has a system cut-off valve 190(optional), which is activated by disconnecting the system for supplyingthe gas flow to the patient (e.g., a nasal cannula) in certain casesfrom lead-through 150. In a case of disconnecting this system (e.g., anasal cannula), for example, such a system cut-off valve allows you toposition a cut-off element in lead-through 150, which prevents theescape of gas. If you connect the system (e.g., a nasal cannula), theconnection can enable a switch or movement of the cut-off element, whichwill open the lead-through 150.

In a specific embodiment of gas valves according to the currentinvention, the equivalent flow rate that can be obtained via a pulsatinggas flow is limited. Most of the time, the current range of availablepneumatic metering valves have the equivalent of a maximum pulsatingflow rate of 5l/min. A number of embodiments can dose the equivalent of6l/min. In some embodiments according to the current invention, highermedical gas flow rates can also be administered in a pulsating regimen,for example, a flow rate of more than 5l/min or 6l/min.

More extensive optimisation that enables pulsating administration withhigher flow rates can achieve a lot of saving. In some embodiments,openings and cavities in valves are therefore dimensioned to providepulsating regimens for higher flow rates. In case of the aforementionedsystem with automatic opening by means of underpressure, the valve ispreferably opened by means of an underpressure of −0.25 to −0.35 cm H₂O.

For the purpose of illustration, the following lists the results of astudy of 63 patients.

To illustrate the advantages of the embodiments of the currentinvention, administration using a gas valve with a metering valve iscompared with a continuous oxygen administration, and the effect of theoxygen therapy and the calculation of the individual saving factor aredetermined.

The study was made using a gas valve with 5 pulsating settings. Thepulsating setting 1 of the gas valve is calibrated in such a manner thatthe administered oxygen bolus has the same effect as 1l/min continuousoxygen therapy. The pulsating setting 2 of the gas valve is calibratedin such a manner that the administered oxygen bolus has the same effectas 2l/min continuous oxygen therapy. The pulsating setting 3 of the gasvalve is calibrated in such a manner that the administered oxygen bolushas the same effect as 3l/min continuous oxygen therapy. The pulsatingsetting 4 of the gas valve is calibrated in such a manner that theadministered oxygen bolus has the same effect as 4l/min continuousoxygen therapy. The pulsating setting 5 of the gas valve is calibratedin such a manner that the administered oxygen bolus has the same effectas 5l/min continuous oxygen therapy. Five categories of therapies werecompared: 1, 2, 3, 4 and 5l/min of continuous oxygen administration werecompared with the metering valve in settings 1, 2, 3, 4 and 5 forpulsating administration. When saturation was measured, each patient gotthe prescribed continuous flow and subsequently, the equivalent of thepulsating mode (e.g., 3l/min continuous mode versus setting 3). FIG. 4shows the average saturation values in continuous mode versus pulsatingmode. The light-coloured bars at the left-hand side show the averagesaturation value with continuous oxygen therapy and the dark-colouredbars at the right-hand side show the average saturation value withpulsating therapy. The saturation values with pulsating therapy comparedto the saturation values with continuous therapy did not showsignificant statistical differences. This illustrates the qualitativeoxygen administration that can be achieved with a pulsating system.

However, it was determined that the oxygen consumption showed an averagedecrease by a factor 5 compared to the continuous oxygen flow, while themeasuring of saturation values in oxygen therapy did not show adifference. This is illustrated in FIG. 5 . The light-coloured bars atthe left-hand side show the measured consumption in continuous mode (#oflitres in 10 minutes). The dark-coloured bars in the centre show themeasured consumption in pulsating mode (#of litres in 10 minutes). Thewhite bars at the right-hand side show the saving factor. It can bededucted from this that pulsating administration that only uses 20% ofthe oxygen (i.e., 80% oxygen saving) achieves the same therapeuticeffect as continuous administration.

In addition—as an experiment for determining the potential savingfactor—the valves according to embodiments of the current invention weretested in a surgery ward of low-care cardiology during 4 months. Thisward had 26 beds. A mass flow meter and a data logger followed theconsumption of the ward over a period of 16 weeks. Furthermore, everychange in therapy during the measuring period was carefully recorded. Inthe odd weeks, the classic system of only continuous flow was used. Inthe even weeks, the valves according to embodiments of the currentinvention with the possibility of continuous and pulsating flow wereused.

The results are shown in FIG. 7 , which provides an overview of themeasured average consumption of the ward during the monitoring period(X-axis), and in FIG. 8 , which provides an overview of the averageconsumption (in litres/minute) of the ward during the periods in whichthe classic system was used (continuous flow according to the state oftechnology) and during the periods in which the current system accordingto the current invention was used (providing the possibility ofcontinuous and pulsating flow). Subsequently, the results of thepulsating system were normalized so that changes in the number ofpatients and the dosage used did not impact further analysis. It emergesfrom the time-dependent results of FIG. 7 and from the averageconsumption of FIG. 8 that a significant oxygen saving was achieved. Therecorded average oxygen saving in the measuring period of 4 months wasapproximately 75%.

By way of illustration, the inner structure of a gas valve according toan embodiment of the present invention as shown in FIG. 6 is illustratedin FIG. 9 a and FIG. 9 b , whereby in FIG. 9A two cross-sections areshown of the inner portion of the valve in pulsating supply operationand in FIG. 9B two cross-sections are shown of the inner portion of thevalve in continuous supply operation. The inner portion of the pulsatingmechanism is not shown in FIG. 9 a and FIG. 9 b for the gas valve of thecurrent example. The regulating system consists in the present exampleof a shiftable selection ring, whereby shifting up or down allowsselection between pulsating and continuous mode. By rotating theselection ring, a selection further can be made of the preferred flowrate or a flow rate equivalent thereto. Rotation of the selection ringwhen it is in the downwards position results in control of a needlevalve for controlling a continuous supply of medical gas. It is to benoticed that alternatively such control of the continuous supply canalso be provided using a different mechanism, such as for example basedon flow through calibrated apertures. Rotation of the selection ringwhen it is in the upward position results in control of the flow rateduring pulsating operation. The pulsating mechanism is not shownexplicitly in the drawing but can be based on known pulse generatingtechniques.

The regulating system 120 comprises a selection valve 920—as shown inFIG. 9 a —allowing selection between continuous operation and pulsatingoperation based on positioning of the selection ring.

A quick fitting mechanism 930 also is shown in FIG. 9 a , the quickfitting mechanism being a component of the connection component—allowingcoupling of the valve to the external supply. A pressure drop regulatingsystem 940 allows a reduction of the input pressure. Furthermore, alsothe internal structure of the flow rate meter 950 is visible. In FIG. 9b a needle valve 960 also is shown, by which the flow rate of thecontinuous supply can be provided.

In operation, the medical gas flows from the connection component 110,through the flow rate meter towards an internal portion of the gas valvedetermined by the selected mode and selected using the selectionmechanism, such that the medical gas flow can be converted in a pulsatedgas flow or a controlled continuous gas flow. The gas flow—being pulsedor continuous according to the selected mode—is then guided to an outletfor supplying to a patient, typically using a nasal cannula.

Further by way of illustration, FIG. 10 and FIG. 11 show anotherembodiment of a gas valve system. The gas valve system shows the inputportion and the gas regulating system which is implemented as a singlecontrol element. The gas valve system is show in front view (left handside) and in cross-sectional view (right hand side) in FIG. 10 . Thedetailed features of the internal part of the remaining part of the gasvalve system are not shown. The single control element allows forcontrolling both the continuous flow and the pulsating flow, i.e. bycounterclock rotation selection can be performed of different flow ratesfor continuous flow, whereby by clockwise rotation, selection can beperformed of different flow rates for pulsating flow. In the presentembodiments, the two sub-regulating systems allow for a selection of aspecific continuous flow mode or a selection of a specific pulsatingflow mode without a previous setting of the other influencing theoutcome.

In yet another embodiment, an alternative gas valve system is shown,wherein the first and second sub-regulating system are implemented as aselection ring and a flow rate meter, arranged in series. The selectionring allows for selecting between different pulsating flow rates or toswitch to continuous mode. The flow rate meter allows for appropriateselection of the flow rate in the continuous mode. An advantage of bothsub-systems being implemented in series is that when the flow rate meteris set to a sufficiently high rate, this flow meter also provides anindication of the amount of medical gas used during operation. Inaddition thereto it also provides a visual indication of properoperation of the on-demand, pulsating flow. The system is illustrated inFIG. 12 .

The invention claimed is:
 1. A gas valve adapted for controlling a flowof a medical gas for oxygen therapy in case of spontaneous breathing,the gas valve comprising: a connection component for connecting the gasvalve to an external supply, a regulating system configured forselecting and supplying a pulsating flow of medical gas or a continuousflow of medical gas, in which the regulating system comprises a firstsub-regulating system for supplying a pulsating flow and a secondsub-regulating system for supplying a continuous flow, wherein the firstsub-regulating system and the second sub-regulating system areimplemented by a control element, and wherein the control element is arotating element and wherein selection in the first sub-regulatingsystem is performed by rotating the control element in a first directionwhile selection in the second sub-regulating system is performed byrotating the control element in the other direction.
 2. The gas valveaccording to claim 1, wherein the first sub-regulating system and thesecond sub-regulating system are controlled by two distinct actions inthe regulating system.
 3. The gas valve according to claim 1, whereinthe second sub-regulating system is a flow rate regulator equipped forat least controllably selecting the flow rate of the continuous flow ina range of 2 litres per minute to 8 litres per minute.
 4. The gas valveaccording to claim 1, wherein the second sub-regulating system is a flowrate meter.
 5. The gas valve according to claim 4, wherein the gas valvefurthermore is configured so that the second sub-regulating systemindicates an amount of medical gas used during a pulsating flow regime.6. The gas valve according to claim 1, wherein the flow rate of a pulsedflow and/or a flow rate of the continuous flow is selectable in astepwise manner.
 7. The gas valve according to claim 1, wherein a stateof the first sub-regulating system does not influence a setting of thesecond sub-regulating system when the second sub-regulating system isused for controlling a continuous flow.
 8. The gas valve according toclaim 1, wherein a state of the second sub-regulating system does notinfluence a setting of the first sub-regulating system when the firstsub-regulating system is used for controlling a pulsed flow.
 9. A gasvalve according to claim 1, wherein the first direction is one of aclockwise or counterclockwise direction of the rotating element andwherein the second direction is the other of the clockwise orcounterclockwise direction of the rotating element.
 10. A gas valveaccording to claim 1, wherein the gas valve is adapted for allowingoxygen therapy in case of spontaneous breathing, wherein the pulsatingflow of medical gas is being based on underpressure generated byinhalation of a patient.
 11. A gas valve according to claim 1, whereinthe second sub-regulating system is adapted for enabling a flow rate ofmore than 10 litres of medical gas per minute.
 12. A gas valve accordingto claim 1, wherein the gas valve is configured so that the firstsub-regulating system and the second sub-regulating system are appliedin parallel gas channels.
 13. A gas valve according to claim 1, whereinthe gas valve system is configured for automatically initiating thevalve in pulsating mode.
 14. The gas valve according to claim 1, whereinthe gas valve is based on solely mechanical and pneumatic operation. 15.A gas valve according to claim 13, wherein the gas valve is adapted forclosing the pulsating flow on the basis of a pre-determined signal. 16.A gas valve according to claim 1, wherein the gas valve comprises asystem cut-off valve for cutting off the gas flow, which is activated bydisconnecting the one-channel nasal cannula or the two-channel nasalcannula from the one-channel feedthrough or two-channel feedthrough. 17.A gas valve according to claim 1, wherein the gas valve is provided witha one-channel feedthrough in order to connect a one-channel nasalcannula for supplying medical gas to a patient or where the gas valve isprovided with a two-channel feedthrough in order to connect atwo-channel nasal cannula for supplying medical gas.
 18. A gas valveaccording to claim 1, wherein the connection component is adjusted forconnecting the gas valve to an external supply network of medical gasesat a pressure lower than 50 bars.